Photographic camera.



PATBNTED SEPT. 19, 1905.

A. D. DAVIS. PHOTOGRAPHIG CAMERA.

APPLICATION 11.21) APR.18,1901.

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PATENTED SEPT. 19, 1905.

A. D. DAVIS.

PHOTOGRAPHIC CAMERA APPLICATION FILED APR.18.1901.

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PATENTED SEPT. 19, 1905.

A. D. DAVIS. PHOTOGRAPHIC CAMERA.

APPLICATION FILED APB.18,1901.

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UNITED STATB PATENT OFFICE.

ALBERT D. DAVIS, OF YONKERS, NEW YORK, ASSIGNOR OF ONE-HALF TOPHOTOGRAPHIC CAMERA.

Specification of Letters Patent.

Patented Sept. 19, 1905.

Application filed April 18, 1901, fierial No. 56,460.

To all whom it Nuty concern:

Be it known that I, ALBERT D. DAvIs, a citi- Zen of the United States,residing at Yonkers, in the county of \Vestchester and State of NewYork, have invented certain new and useful Improvements in PhotographicCameras; and I do declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanyingdrawings, and to the figures of reference markedthereon, which form a part of this specification.

My invention relates to photographic cameras, and is particularlyadapted for such cameras of the folding type; and it has primarily forits object to provide for the adjustment of a projecting lens and afinder-lens relatively to each other and with reference to a graduatedscale or index indicating the difference in the focus of the two lensesso that when onelens is adjusted to any given point and the other lensis adjusted to a given point bearing a certain relation to the otherpoint the two lenses Will have the same effect as lenses havingpractically the same focus, notwithstanding the fact that one of thelenses in itself has a different focus from the other lens.

It has also for its object to provide novel and useful features ofconstruction and also of arrangements of parts, adapting thefirst-mentioned object to be readily attained, and it has further forits object to provide improved features, forming a camera possessingadvantages which will appear from the description of the partshereinafter given, the invention being applicable to cameras already inuse, as Well as to those which may be constructed in the first instancein accordance with my invention.

Heretofore focusing-finders have been employed in cameras; but in suchcases it has been assumed that lenses each having exactly the same focuscould be found in sufficient commercial quantities to supply the demand,and hence no provision has been made for overcoming the difficultiesexperienced when the projecting-lens and the finder-lens in the samecameras are not of exactly the same foci, which difficulties are markedand quite serious in many cases and become more pronounced and varyingin degree as the lens is moved beyond a certain point in the operationof focusing. As an illustration of cameras in which these difficultiesare experienced mention may be made of twin-lens cameras, commonlyreferred to in the trade as doubledeckers, and also to other cameras inwhich a projecting-lens and a finder-lens are employed. There are a verylarge number of camerasin use that would be more convenient andsatisfactory and give more accurate results if a suitable finder couldbe readily obtained that would independently determine positively thedistance of the object to be photographed away from the sensitive plateand that could be attached to a camera with focusing-scales for theprojecting-lens and the finder lens, arranged so as to be viewed at oneand the same time, and mechanism be employed that would readilybringboth lenses to asharp focus on the composition of the scene orpicture to be taken. A twin-lens camera to some extent accomplishes thisresult, where an expensive lens is employed for projecting the pictureon the sensitive plate; but an equally expensive lens of the sameprescription must be employed for the finder and both must have the samefoci for determining what is the sharp focus of the projecting lens.Even where these expensive lenses are employed they at times fail togive the result desired, as it more frequently happens that no twolenses are made exactly alike, even if the same prescription is followedas closely as the mechanical means employed will admit, and while it maybe possible to find two lenses with equal focus and in every way alike,yet the fact remains that they are not obtained in quantities, and thusto obtain two lenses of exactly the same focal length resort must be hadto expen-- sive or high-priced types of lenses, which are indispensableto rapid work in the absence of my invention. 1 therefore seek to overcome these objections by providing an improvement in which the findercan be made cheaply and can be so nearly worked in concert with the lensto be matched that the operator is not embarrassed with the differenceexisting between the projecting and the finder lenses to such an extentas to retard his rapid work.

The principal cameras of to-day are supplied with focusing mediums fortripod use where the screen takes the place of the sensitive plate, andusually a finder is provided that merely locates the picture withrespect to the one to be projected onto the plate, and some of thesefinders fold in the camera when not in use; but, so far as I am aware,prior to my invention no provision had been made for the adjustment ofthe projecting-lens and the finder-lens relative to each other in themanner I have heretofore indicated, so that the two lenses will have thesame effect as lenses having practically the same foci, notwithstandingthat one of the lenses in itself has a different focus from the otherlens.

In providing the scale for use with the lenses in the manner I haveindicated the I first step is to focus the projecting lens at its focallength and at all distances shorter than the same and provide a scaleaccordingly, then focus the finder to be used (the lens contained inwhich should be as nearly like the first-mentioned lens as to focallength as possible) at all the different distances and pro vide a scalefor the latter; then locate the respective scales as near the same lineof vision as possible. The projecting-lens and the finder-lens bothbeing provided with indexes or pointers to cooperate with theirrespective scales, the parts are ready for operation, and in order toeffect the focusing the finder is adjusted to the point that gives asharp focus, which point is shown on the scale by the index or finger ofthe finder, and such point determines the correspondinglymarked point towhich the other or projecting-lens should be brought, and when broughtto such point it will be found that the efiect will be the same as ifthe two lenses were each of practically the same focus.

In the drawings, which contain an illustration of my invention, Figure 1is a side elevation of a folding camera with the front lid or doorlowered to operative position with my invention applied thereto. Fig. 2is a front elevation of the same. Fig. 3 is a plan view of a portion ofthe camera to illustrate more clearly certain details. Fig. 4 is a sideelevation of a camera similar to Fig. 1, but showing certainmodifications in which the finder is adapted to be thrown to one side ofthe side of the camera-box. Fig. 5 is a plan view of Fig. 1. Fig. 6 is afront elevation of the same. Fig. 7 is a longitudinal section, partlyinelevation, of a finder that may be used with my invention. Fig. 8 is arear elevation of the finder. Fig. 9 is a detail view showing a furthermodification in the means for moving or adjusting the finder and theprojecting-lens. Fig. 10 is a detail of a modified means of attachingthe index-finger to the finder.

In the drawings, the numeral 1 designates the camera-box; 2, the foldingbellows; 3, the projecting-lens frame, which is supported by theslide-bracket 4: upon the guide-plate 5, all of which parts may be ofany approved pattern, and 6 designates the hinged lid, which isconnected with the camera-box by a brace 7, as usual, and 8 indicatesthe projecting-lens.

The numeral 9 designates a finder, which in this instance is providedwith the mirror 10 and the ground glass 11, as common in many finders.In Figs. 1 to 3 this finder is secured to the lid 6 and is within rangeof the vision of the operator looking over the top of the camera-box,with the hinged portion 12 of the top thrown back from the positionillustrated in Fig. 1. This finder is adapted to be folded inside of thecamera-box when the lid is closed, and it is provided with thetelescoping sections or tubes 13 and 14, which may be provided with thefocusing-lens 15 and a condensing-lens 16, as illustrated in Fig. 7 ofthe drawings.

In Figs. 1 to 3 the telescoping parts of the finder are moved back andforth by means of a pinion 17 engaging a rack 18 on the lower part ofthe telescoping section 13, said pinion being at one end of a hollowshaft 19, provided at its other end with a thumb-piece 20, the shaftbeing journaled in a bearing 21, so that it may slide therein in orderthat when the lid 6 is to be closed the shaft and pinion may be movedinwardly, so as to permit the same to move inside of the camera-box, thepinion being of elongated form, so that it may remain in engagement withthe rack in its inner and outer positions. Through the hollow shaft 19and the pinion 17 passes another shaft 22, which has a pinion 23, thatengages a rack 24, attached to the slide of the bracket 4:, so that theprojecting-lens and the bellows, to which it is attached, may be movedback and forth, the outer end of the shaft 22 being provided with athumb-piece 25, by which it may be turned. This shaft is also adapted tobe slid in and out, so that when moved inward the parts may fit withinthe camera-box, the inner end of the shaft 22 being journaled in thebearing 26 and the pinion 23 being of elongated form, so as to keep inengagement with the rack 24 in the outer and inner adjustment of thepinion. By arranging the two shafts as described the thumb-pieces ofboth shafts are brought close together, so that both may be grasped atthe same time by the thumb and forefinger in order to move thefinderlens and the projecting-lens in and outsimultaneously and at thesame time permit one shaft to be turned independently of the other inthe adjustment of the finder-lens and then in the adjustment of theprojecting-lens, so as to bring it in proper relation to the finderlensto give to the two lenses of different foci the effect of two lenses ofsubstantially the same foci, after which the two lenses may be movedsimultaneously by grasping at the same time the thumb-pieces of the twoshafts. The numeral 27 designates a scale which is graduated accordingto the differences in focus of the finder-lens and the projecting-lens,with which scale cooperates an index or linger 28 on the finder and anindex or finger 29 on the lens-frame or other part movable with theprojecting-lens, so that when the finder-lens is adjusted to a certainpoint, indicated by its finger on the graduated scale, theprojectinglens may be adjusted to a certain position in relation to thatpoint, as indicated by its index or finger being moved to the graduationcorresponding with that indicated by the finger of the finder-lens, thegraduations being such as before indicated to indicate the differencesin the foci of the two lenses. After the two have been adjusted asindicated then they may be moved together, as before specified. If itshould happen that the projecting-lens and the finder-lens are of thesame focus, then in that event the two lenses may be movedsimultaneously by the shafts of the two pinions, and thus it will appearthat the construction is such that it may be used where the two lensesare of the same focus or where they are different and it is necessary toadjust one in relation to the other, so as to give the same effect as ifthe two were of the same focus.

In Figs. 4 to 8 of the drawings I have illustrated another constructionembodying the same invention as that already described for theadjustment of the two lenseswhere they are each of a different focus, ascale 27 being provided, as in the form just described, and an index orfinger 29 for the projecting lens and an index or finger 30 for thefinder, the index or finger 30 in this form having a pivotal connectionwith one of the telescoping sections of the finder-lens either by apivotpin 31, as shown in Fig. 10, or by a springclasp 32, as shown inFig. 5', which will permit the finger to be turned on the telescopingsection so as to permit the finder in its modified form to be foldedupon the lid or cover 6, so as to be carried within the camera-box whenthe lid is closed or to be folded or swung outwardly when the lid islowered for use of the camera, as indicated in Figs. 4 and 5 of thedrawings. In this folding or swinging form of the finder the rearportion 33 of the finder fits within a ring 34, which is hinged by ascrew or pin 35 or otherwise to a bracket 36, which is secured to thelid 6 of the camerabox, so that when the lid is lowered the finder maybe swung outward to one side of the lid, as indicated in Figs. 5, 6, and8 of the drawings, thus enabling the operator to take his vision fromone side of the camera-box. In this modified form the telescopingsection 13 of the finder will be racked back and forth by means of thepinion 37 engaging the rack 38 on the top of the telescoping section,the shaft 39 of said pinion being journaled in the bearings 40 andhaving the thumb-piece 41, while the projecting-lens will be racked backand forth by the pinion 42 engaging the rack 43, attached to the lid,the shaft 44 of said pinion being journaled in suitable bearings 45 andhaving a sliding sleeve 46, provided with the thumb-piece 47, so as torack the lens back and forth, the sliding sleeve permitting thethumb-piece to be moved inward, so that it may lie within the camera-boxwhen the lid is closed. In order to permit the finder to be turned sothat either a vertical or horizontal picture may be taken, the rearportion 33 of the finder turns within the ring 34, and for the purposeof holding the finder in position a spring 48 is secured to the ring 34and has a pin 49, extending through the ring and adapted to engage adepression in the rear part 33 of the finder, so as to hold the finderin its turned position. The operation of this form of the invention inorder to adjust the two lenses one in relation to the other, so as togive to the lenses of different focal lengths the same effect as if ofpractically the same focal length each, is practically the same as underthe form first described, and therefore needs no further description.

Instead of providing the projecting-lens and the finder with the pinionsand shafts separated from each other, as in Fig. 5, for adjustment ofsaid parts I may employ the construction illustrated in Fig. 9, which issubstantially the same as that indicated in Fig. 2 of the drawings, thefinder being racked back and forth by the pinion 50 on the end of theshaft 51, which shaft at its outer end is provided with a thumb-piece52, said shaft passing through the hollow shaft 53, which has a pinion54 to engage the rack of the slide to the bracket and at its outer endprovided with the thumb-piece 55 for manipulating the same. It will thusbe observed that these several parts are substantially the same as thecorresponding parts illustrated in Fig. 2 of the drawings.

I have illustrated and described with particularity the preferreddetails of construction and arrangement of the several parts; but it isobvious that such changes can be made therein as will fall within thescope of the appended claims.

Having described my invention and set forth its merits, what I claimis 1. A camera having a finder mounted thereon and a projecting-lens,each capable of being focused independently, and means whereby thefocusing of the finder-lens will indicate the corresponding point towhich the projectinglens should be brought to give to the two lenses theeffect of lenses of practically the same focus, substantially asdescribed.

2. A camera having a finder mounted thereon and a projecting-lens, eachadapted to be focused independently, a scale indicating the focus ofeach of the lenses. and means for focusing the lenses, substantially asdescribed.

3. In a camera having a finder and a projecting-lens adapted to befocused independently,

'a scale indicating the focus of each of the lenses, an index or fingerfor the finder and the projecting-lens each, and means for adjusting thetwo lenses to points indicating the same focus, substantially asdescribed.

4. In a camera having a finder and a projecting-lens adapted to befocused independently, a scale imlicating the focus of each of thelenses, and means adapted to focus the lenses independently or in unisonas desired, substantially as described.

5. In a camera, a finder and a projecting-lens inde iiendentlyadjustable, a scale indicating the focus of each of the lenses, andmeans provided with manipulating thumb-pieces located contiguous to eachother to enable one or both thumb-pieces to be grasped by the thumb andfinger to move the lenses independently or in unison as desired,substantially as described.

6. In a camera having a finder and a projecting-lens independentlyadjustable, a scale indicating the focus of each of the lenses,a hollowshaft and pinion for moving one of the lenses and a shaft passingthrough the hollow shaft and having a pinion for moving the lens, saidALBERT D. DAVIS.

W'itnesses:

WVM. Gr. HnNDERsoN, GEO. WV. REA.

